1 /*
2 * Copyright (C) 2010 Apple Inc. All rights reserved.
3 * Copyright (c) 2010 University of Szeged
4 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
25 * THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "config.h"
29 #include "SharedMemory.h"
30
31 #include "ArgumentDecoder.h"
32 #include "ArgumentEncoder.h"
33 #include "WebCoreArgumentCoders.h"
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <stdlib.h>
37 #include <sys/mman.h>
38 #include <sys/stat.h>
39 #include <sys/types.h>
40 #include <unistd.h>
41 #include <wtf/Assertions.h>
42 #include <wtf/CurrentTime.h>
43
44 #if PLATFORM(QT)
45 #include <QDir>
46 #elif PLATFORM(GTK)
47 #include <wtf/gobject/GOwnPtr.h>
48 #endif
49
50 namespace WebKit {
51
Handle()52 SharedMemory::Handle::Handle()
53 : m_fileDescriptor(-1)
54 , m_size(0)
55 {
56 }
57
~Handle()58 SharedMemory::Handle::~Handle()
59 {
60 if (!isNull())
61 while (close(m_fileDescriptor) == -1 && errno == EINTR) { }
62 }
63
isNull() const64 bool SharedMemory::Handle::isNull() const
65 {
66 return m_fileDescriptor == -1;
67 }
68
encode(CoreIPC::ArgumentEncoder * encoder) const69 void SharedMemory::Handle::encode(CoreIPC::ArgumentEncoder* encoder) const
70 {
71 ASSERT(!isNull());
72
73 encoder->encode(releaseToAttachment());
74 }
75
decode(CoreIPC::ArgumentDecoder * decoder,Handle & handle)76 bool SharedMemory::Handle::decode(CoreIPC::ArgumentDecoder* decoder, Handle& handle)
77 {
78 ASSERT_ARG(handle, !handle.m_size);
79 ASSERT_ARG(handle, handle.isNull());
80
81 CoreIPC::Attachment attachment;
82 if (!decoder->decode(attachment))
83 return false;
84
85 handle.adoptFromAttachment(attachment.releaseFileDescriptor(), attachment.size());
86 return true;
87 }
88
releaseToAttachment() const89 CoreIPC::Attachment SharedMemory::Handle::releaseToAttachment() const
90 {
91 ASSERT(!isNull());
92
93 int temp = m_fileDescriptor;
94 m_fileDescriptor = -1;
95 return CoreIPC::Attachment(temp, m_size);
96 }
97
adoptFromAttachment(int fileDescriptor,size_t size)98 void SharedMemory::Handle::adoptFromAttachment(int fileDescriptor, size_t size)
99 {
100 ASSERT(!m_size);
101 ASSERT(isNull());
102
103 m_fileDescriptor = fileDescriptor;
104 m_size = size;
105 }
106
create(size_t size)107 PassRefPtr<SharedMemory> SharedMemory::create(size_t size)
108 {
109 #if PLATFORM(QT)
110 QString tempName = QDir::temp().filePath(QLatin1String("qwkshm.XXXXXX"));
111 QByteArray tempNameCSTR = tempName.toLocal8Bit();
112 char* tempNameC = tempNameCSTR.data();
113 #elif PLATFORM(GTK)
114 GOwnPtr<gchar> tempName(g_build_filename(g_get_tmp_dir(), "WK2SharedMemoryXXXXXX", NULL));
115 gchar* tempNameC = tempName.get();
116 #endif
117
118 int fileDescriptor;
119 while ((fileDescriptor = mkstemp(tempNameC)) == -1) {
120 if (errno != EINTR)
121 return 0;
122 }
123 while (fcntl(fileDescriptor, F_SETFD, FD_CLOEXEC) == -1) {
124 if (errno != EINTR) {
125 while (close(fileDescriptor) == -1 && errno == EINTR) { }
126 unlink(tempNameC);
127 return 0;
128 }
129 }
130
131 while (ftruncate(fileDescriptor, size) == -1) {
132 if (errno != EINTR) {
133 while (close(fileDescriptor) == -1 && errno == EINTR) { }
134 unlink(tempNameC);
135 return 0;
136 }
137 }
138
139 void* data = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileDescriptor, 0);
140 if (data == MAP_FAILED) {
141 while (close(fileDescriptor) == -1 && errno == EINTR) { }
142 unlink(tempNameC);
143 return 0;
144 }
145
146 unlink(tempNameC);
147
148 RefPtr<SharedMemory> instance = adoptRef(new SharedMemory());
149 instance->m_data = data;
150 instance->m_fileDescriptor = fileDescriptor;
151 instance->m_size = size;
152 return instance.release();
153 }
154
accessModeMMap(SharedMemory::Protection protection)155 static inline int accessModeMMap(SharedMemory::Protection protection)
156 {
157 switch (protection) {
158 case SharedMemory::ReadOnly:
159 return PROT_READ;
160 case SharedMemory::ReadWrite:
161 return PROT_READ | PROT_WRITE;
162 }
163
164 ASSERT_NOT_REACHED();
165 return PROT_READ | PROT_WRITE;
166 }
167
create(const Handle & handle,Protection protection)168 PassRefPtr<SharedMemory> SharedMemory::create(const Handle& handle, Protection protection)
169 {
170 ASSERT(!handle.isNull());
171
172 void* data = mmap(0, handle.m_size, accessModeMMap(protection), MAP_SHARED, handle.m_fileDescriptor, 0);
173 if (data == MAP_FAILED)
174 return 0;
175
176 RefPtr<SharedMemory> instance = adoptRef(new SharedMemory());
177 instance->m_data = data;
178 instance->m_fileDescriptor = handle.m_fileDescriptor;
179 instance->m_size = handle.m_size;
180 handle.m_fileDescriptor = -1;
181 return instance;
182 }
183
~SharedMemory()184 SharedMemory::~SharedMemory()
185 {
186 munmap(m_data, m_size);
187 while (close(m_fileDescriptor) == -1 && errno == EINTR) { }
188 }
189
accessModeFile(SharedMemory::Protection protection)190 static inline int accessModeFile(SharedMemory::Protection protection)
191 {
192 switch (protection) {
193 case SharedMemory::ReadOnly:
194 return O_RDONLY;
195 case SharedMemory::ReadWrite:
196 return O_RDWR;
197 }
198
199 ASSERT_NOT_REACHED();
200 return O_RDWR;
201 }
202
createHandle(Handle & handle,Protection protection)203 bool SharedMemory::createHandle(Handle& handle, Protection protection)
204 {
205 ASSERT_ARG(handle, !handle.m_size);
206 ASSERT_ARG(handle, handle.isNull());
207
208 int duplicatedHandle;
209 while ((duplicatedHandle = dup(m_fileDescriptor)) == -1) {
210 if (errno != EINTR) {
211 ASSERT_NOT_REACHED();
212 return false;
213 }
214 }
215
216 while ((fcntl(duplicatedHandle, F_SETFD, FD_CLOEXEC | accessModeFile(protection)) == -1)) {
217 if (errno != EINTR) {
218 ASSERT_NOT_REACHED();
219 while (close(duplicatedHandle) == -1 && errno == EINTR) { }
220 return false;
221 }
222 }
223 handle.m_fileDescriptor = duplicatedHandle;
224 handle.m_size = m_size;
225 return true;
226 }
227
systemPageSize()228 unsigned SharedMemory::systemPageSize()
229 {
230 static unsigned pageSize = 0;
231
232 if (!pageSize)
233 pageSize = getpagesize();
234
235 return pageSize;
236 }
237
238 } // namespace WebKit
239